INDIANAPOLIS (AP) _ The Indiana Court of Appeals says state environmental regulators improperly changed state rules to allow Indiana ethanol refineries to release an extra 150 tons of air pollutants per year.

The appeals court Tuesday overturned a lower court ruling that allowed the Indiana Department of Environmental Management to reclassify ethanol refineries so they could emit 250 tons of pollutants per year rather than the 100-ton limit that applies to ``chemical process plants.''

The Natural Resources Defense Council had challenged the reclassifications of Poet Biorefining plants in North Manchester and Cloverdale.

The reclassifications appeared to be consistent with an U.S. Environmental Protection Agency rule, but the court ruled IDEM failed to get EPA approval on how it implements the federal rule.